Vic and Monica go head to head with Antwon, and do everything in their power to get him to admit to being involved with the cop killings. Monica is shocked when Vic and Shane confront her with the information they've been hiding regarding Antwon and Angie's body. Shane and Army wonder if they'll be able to pass the lie detector test Monica is forcing them to take. Meanwhile, after another young black woman is murdered, Dutch and Claudette hope to prove their suspicions correct with their recently relocated Texan.

Vic and the Strike Team use their leverage on the One-Niners to track down anyone involved with the cop killings. Their hunt leads them down an unexpected path with the Russian mob. Monica puts pressure on the team to come clean about any of their dealings with Antwon. Dutch and Claudette investigate a gang shooting and soon realize their key witness is close to the Barn, and has something to hide.

Monica, Vic and the strike team work together to put Antwon Mitchell back behind bars after his deal with the DEA released him from prison. When Vic reveals his suspicions of David's connection to both Antwon and an inmate's murder, David must protect his political future at any cost. When the murder of an over-protective father leads Claudette and Dutch back to a foster home they had previously investigated, Monica makes an unpopular decision that helps seal her fate.

As racial tension in the area escalates, the Strike Team attempts to end a race war, while Claudette and Dutch investigate a riot at a high school. Meanwhile, an Internal Affairs officer begins his investigation of Vic and the Strike Team by first zeroing in on Lem. A pregnant Danny refuses to reveal the identity of the father, and Julien begins training a rookie cop named Tina Hanlon.

During an interrogation, Kavanaugh reviews the Strike Team’s corrupt past and attempts to weaken Lem’s loyalty to Vic by bringing up the connection to Terry’s murder. Meanwhile, the Strike Team investigates a multiple homicide. Dutch and Claudette suspect that a minister might have been involved in an attempted murder. Tina gets in over her head while on duty with Julien.

With the IAD investigation in full force, Vic seeks legal representation from Becca Doyle for the Strike Team. Also, a suspicious Vic decides to confront Emolia after he begins to doubt her loyalty to him. Meanwhile, Dutch and Claudette investigate the ghastly murder of a pregnant woman. Tina continues to make mistakes while on duty.

Via a bug planted in the clubhouse, Kavanaugh monitors the Strike Team as they investigate an illegal prescription drug ring that is proving to be deadly for the people of Farmington. While working on a missing person’s case, Dutch attempts find out what Claudette is hiding.

Kavanaugh seeks the help of Antwon Mitchell in his ongoing quest to take down the Strike Team. In the midst of this, Kavanaugh has a lot on his mind as his ex-wife reenters the picture, and he reluctantly agrees to let Vic send Emolia undercover to infiltrate a Salvadoran gang that is stockpiling grenades.

As Vic prepares to help Lem get out of the country to begin a new life in Mexico; Kavanaugh and Aceveda attempt to capitalize on the situation by using this as means to try to take down the leader of the Strike Team. Dutch decides to file for a transfer. Meanwhile, Shane tries to cut off the investigation by taking extreme measures and Danny finally confronts the father of her child.

With the Barn grieving over the loss of one of their own, Vic's out to avenge his friend's murder, but finds himself in the crosshairs of Kavanaugh. Claudette assigns the Strike Team to investigate the torching of a methadone clinic. Meanwhile, Julien and Tina look into a robbery/assault at a porno shop, and Dutch makes a horrifying discovery in San Marcos.

Kavanaugh acquires what he needs in order to apprehend Vic who is preoccupied with getting revenge on Guardo. Claudette finds herself under the political microscope as a result of the San Marcos incident, and Danny receives some news about her future at the Barn.